Oil and gas well casing pipe sealing device

The utility model provides an oil and gas well casing pipe sealing device which comprises a central pipe, a fixing ring, a deformation sealing mechanism and a push ring, the fixing ring, the deformation sealing mechanism and the push ring are sequentially arranged on the central pipe in a sleeved mode, the deformation sealing mechanism comprises a rubber cylinder and a spring, and the rubber cylinder and the spring are both arranged on the central pipe in a sleeved mode; and in a working state, the spring is in a compressed state, and the fixed ring and the push ring are both fixed on the central pipe. In the installed and used state, the spring is in the compressed state, the rubber cylinder is extruded to deform, open holes in the sleeves on the periphery of the central pipe or a gap in the connecting position of the two sleeves can be blocked, and when the rubber cylinder is gradually aged and creeped in the long-term high-temperature and extrusion environment, the risk that the sealing performance is redu